HANDLED

The key event was handled and its further propagation should be stopped.

NOT_HANDLED

The key event wasn't handled and should be delivered to other clients or listeners.

PRESSED

Key is actuated.

Receiving this event type means that a key has been actuated at the timestamp when the event is received, and while the event recipient is focused.

For example, if the key is a keyboard key, then it was just pressed.

RELEASED

Key is no longer actuated.

Receiving this event type means that a key has been de-actuated at the timestamp when the event is received, and while the event recipient is focused.

For example, if the key is a keyboard key, then it was just released.

SYNC

Key was actuated while the client wasn't able to receive it, and is still actuated now that the client is able to receive key events.

This may happen in a few ways:

- A new device was connected while its key was actuated.
- The key was actuated while the event recipient did not
  have focus.

Therefore, this is not a "regular" key actuation. It reports now that the key has been actuated in the unknown past. Some event recipients may therefore decide that this is not an actionable key event, while some others may decide that it is.

For example, recipients that trigger some user action may decide to ignore SYNC events, to avoid spurious actions. In contrast, recipients that keep track of the keyboard state may want to consider a SYNC event as a signal to update the key's state to actuated.

CANCEL

Key may have been actuated, but its actuation has become invalid due to an event other than a key de-actuation.

This may happen in a few ways:

- A device was disconnected while its key was actuated.
- The event recipient just lost focus.

Therefore, this is not a "regular" key de-actuation. It reports the key is no longer validly actuated due to an event other than a key release. Some event recipients may therefore decide that this is not an actionable key event, while some others may decide that it is.

For example, recipients which trigger some user action may decide to ignore CANCEL events, to avoid spurious actions. In contrast, recipients that keep track of the keyboard state may want to consider a CANCEL event as a signal to update the key's state to being de-actuated.

UNIDENTIFIED

This key value is used when an implementation is unable to identify another key value, due to either hardware, platform, or software constraints.

ALT

The Alt (Alternative) key.

This key enables the alternate modifier function for interpreting concurrent or subsequent keyboard input. This key value is also used for the Apple Option key.

ALT_GRAPH

The Alternate Graphics (AltGr or AltGraph).

This key is used enable the ISO Level 3 shift modifier (the standard Shift key is the level 2 modifier). See ISO9995-1.

CAPS_LOCK

The Caps Lock (Capital) key.

Toggle capital character lock function for interpreting subsequent keyboard input event.

CONTROL

The Control or Ctrl key, to enable control modifier function for interpreting concurrent or subsequent keyboard input.

FN

The Function switch Fn key.

Activating this key simultaneously with another key changes that key’s value to an alternate character or function. This key is often handled directly in the keyboard hardware and does not usually generate key events.

FN_LOCK

The Function-Lock (FnLock or F-Lock) key.

Activating this key switches the mode of the keyboard to changes some keys' values to an alternate character or function. This key is often handled directly in the keyboard hardware and does not usually generate key events.

META

The Meta key, to enable meta modifier function for interpreting concurrent or subsequent keyboard input.

This key value is used for the Windows Logo key and the Apple Command or ⌘ key.

NUM_LOCK

The NumLock or Number Lock key, to toggle numpad mode function for interpreting subsequent keyboard input.

SCROLL_LOCK

The Scroll Lock key, to toggle between scrolling and cursor movement modes.

SHIFT

The Shift key, to enable shift modifier function for interpreting concurrent or subsequent keyboard input.

SYMBOL

The Symbol modifier key (used on some virtual keyboards).

SYMBOL_LOCK

The Symbol Lock key.

HYPER

The Hyper key. A legacy modifier.

SUPER

The Super key. A legacy modifier.

ENTER

The Enter or ↵ key, to activate current selection or accept current input. This key value is also used for the Return (Macintosh numpad) key.

TAB

The Horizontal Tabulation Tab key.

BACKSPACE

Delete the character immediately preceding the cursor (i.e. the character to the left for LTR languages).

DOWN

The down arrow navigation key.

LEFT

The left arrow navigation key.

RIGHT

The right arrow navigation key.

UP

The up arrow navigation key.

END

The "End" key.

HOME

The "Home" key.

PAGE_DOWN

The "Page Down" key.

PAGE_UP

The "Page Up" key.

ESCAPE

The Escape or Esc key.

SELECT

The Select key. Used to select the window of a task to focus on.

BRIGHTNESS_DOWN

The Brightness Down key. Typically controls the display brightness.

BRIGHTNESS_UP

The Brightness Up key. Typically controls the display brightness.

F1

The F1 key, a general purpose function key, as index 1.

F2

The F2 key, a general purpose function key, as index 2.

F3

The F3 key, a general purpose function key, as index 3.

F4

The F4 key, a general purpose function key, as index 4.

F5

The F5 key, a general purpose function key, as index 5.

F6

The F6 key, a general purpose function key, as index 6.

F7

The F7 key, a general purpose function key, as index 7.

F8

The F8 key, a general purpose function key, as index 8.

F9

The F9 key, a general purpose function key, as index 9.

F10

The F10 key, a general purpose function key, as index 10.

F11

The F11 key, a general purpose function key, as index 11.

F12

The F1 key, a general purpose function key, as index 12.

SOFT_1

General purpose virtual function key, as index 1.

SOFT_2

General purpose virtual function key, as index 2.

SOFT_3

General purpose virtual function key, as index 3.

SOFT_4

General purpose virtual function key, as index 4.

MEDIA_PLAY_PAUSE

Pause the currently playing media.

NOTE: Media controller devices should use this value rather than PAUSE for their pause keys.

AUDIO_VOLUME_DOWN

Decrease audio volume.

AUDIO_VOLUME_UP

Increase audio volume.

AUDIO_VOLUME_MUTE

Toggle between muted state and prior volume level.

BROWSER_BACK

Navigate to previous content or page in current history.

BROWSER_FAVORITES

Open the list of browser favorites.

BROWSER_FORWARD

Navigate to next content or page in current history.

BROWSER_HOME

Go to the user’s preferred home page.

BROWSER_REFRESH

Refresh the current page or content.

BROWSER_SEARCH

Call up the user’s preferred search page.

BROWSER_STOP

ZOOM_TOGGLE

Toggle between full-screen and scaled content, or alter magnification level.

1

Time in nanoseconds when the event was recorded, in the CLOCK_MONOTONIC time base. The timestamp is required on every key event, and users can expect that it will always be present.

2

Type of event.

3

Identifies the key ignoring modifiers, layout, prior key events, etc. This is called the "physical key" on some platforms. In cases where the key event did not originate from a physical keyboard (e.g. onscreen keyboard) this field may be empty.

4

Modifiers in effect at the time of the event. Example: CapsLock is off, user presses CapsLock, then A, then releases both. Event sequence is as follows:

1. type: Pressed, key: CapsLock, modifiers: None
2. type: Pressed, key: A, modifiers: CapsLock
3. type: Released, key: CapsLock, modifiers: CapsLock
4. type: Released, key: A, modifiers: CapsLock

CapsLock is on, user presses CapsLock, then A, then releases both.

1. type: Pressed, key: CapsLock, modifiers: CapsLock
2. type: Pressed, key: A, modifiers: None
3. type: Released, key: CapsLock, modifiers: None
4. type: Released, key: A, modifiers: None

5

Meaning of the key.

6

The sequence number of this KeyEvent in the sequence of autorepeated keys.

Unset if this event has been generated in the immediate response to an input from the keyboard driver. If the KeyEvent has been generated through the autorepeat mechanism, this property is set and is incremented by one for each successive generated key event.

7

The lock state in effect at the time of the event.

For example, if CapsLock effect is turned on (pressing 'a' results in the effect 'A'), the corresponding bit in the lock state is set.

NOTE: LockState is different from whether the CapsLock modifier key is actuated or not. LockState.CAPS_LOCK can be active even if the Caps Lock key is not currently actuated.

8

Identifies the device originating this event.

1

The Unicode codepoint representing character typed, if any.

• In Dart and Go, this corresponds to a rune.
• In Rust, this corresponds to a char.
• In C and C++, this corresponds to ICU's UChar32.

2

The meaning of the key for key events with no corresponding symbol.

CAPS_LOCK

Applies when the CAPS_LOCK modifier is locked.

Users should bear in mind that the effect of CAPS_LOCK is limited to alphabetic keys (not even alphanumerics) mainly.

For example, pressing a on a US QWERTY keyboard while CAPS_LOCK state is locked results in the key meaning A, just as if the Shift modifier was used. However, pressing [ when CAPS_LOCK is locked gives [, even though Shift+[ gives {.

The position of alphabetic keys may vary depending on the keymap in current use too.

NUM_LOCK

Applies when the NUM_LOCK modifier is locked.

SCROLL_LOCK

Applies when the SCROLL_LOCK modifier is locked.

FUNCTION_LOCK

Applies when the FUNCTION modifier is locked.

SYMBOL_LOCK

Applies when the SYMBOL modifier is locked.

CAPS_LOCK

Applies when the CAPS_LOCK modifier is actuated.

NUM_LOCK

Applies when the NUM_LOCK modifier is actuated.

SCROLL_LOCK

Applies when the SCROLL_LOCK modifier is actuated.

FUNCTION

Applies when the FUNCTION modifier is actuated.

SYMBOL

Applies when the SYMBOL modifier is actuated.

LEFT_SHIFT

Applies when the left SHIFT modifier is actuated.

RIGHT_SHIFT

Applies when the right SHIFT modifier is actuated.

SHIFT

Applies when either LEFT_SHIFT or RIGHT_SHIFT modifier is actuated.

This bit mask a convenience to test for either LEFT_SHIFT or RIGHT_SHIFT.

LEFT_ALT

Applies when the left ALT modifier is actuated.

RIGHT_ALT

Applies when the right ALT modifier is actuated.

ALT

Applies when either the left ALT or the right ALT modifier is actuated.

ALT_GRAPH

Applies when the ALT_GRAPH modifier is actuated.

LEFT_META

Applies when the LEFT_META modifier is actuated.

RIGHT_META

Applies when the RIGHT_META modifier is actuated.

META

Applies when either LEFT_META or RIGHT_META modifier is actuated.

LEFT_CTRL

Applies when the LEFT_CTRL modifier is actuated.

RIGHT_CTRL

Applies when the RIGHT_CTRL modifier is actuated.

CTRL

Applies when either LEFT_CTRL or RIGHT_CTRL modifier is actuated.